code: def dual_class(self):
      return BarBra
  
imports: from sympy.core.numbers import I, Integer
  from sympy.physics.quantum.innerproduct import InnerProduct
  from sympy.physics.quantum.dagger import Dagger
  from sympy.physics.quantum.state import Bra, Ket, StateBase
label_desc: Use image node_id 1 for calling the BarKet obj's underlying member method code with example usage: obj.dual_class() and returns: BarBra